The multi-way valves and systems are used to control the direction, pressure and flow of hydraulic fluid, which are widely applicable to hydraulic control systems of mobile mechanisms, and significantly influence displacement, rotation, lifting and lowering and other ancillary functions of mobile equipments and transmission mechanisms. So the valves and systems are in the very important and remarkable status.
The traditional multi-way valve products can date from the manual directional valve in industrial hydraulic valves. The structure of them are the combinations of cylinder spool valve main stage with convex shoulders and throttles and complicated casting flow channel valve body with undercutting grooves and throttle ports. In the structure, the ratio of the length and the diameter of cylinder spool valve main stage is excessive, the dimensional accuracy and geometric tolerance is very strict, the throttles are too many and with kinds of shapes, the ratio of the length and the diameter of the valve hole in the complicated casting flow channel valve body is more excessive, the fit between valve hole and spool and the dimensional accuracy and geometric tolerance of related dimensions are much stricter, the axial and circumferential fit between convex shoulders and spool throttles are more complicated. Therefore, the machining of the structure is complicated, the structure is incompliant, the cleanliness and temperature of the oil is hard to control, the structure is very sensitive to the mechanical deformation and this will usually lead to spool seizure and influence use and maintenance. The screw cartridge valves and other “single control elements” and auxiliary elements with embedded structure are widely used in the valve body to combine valve system products with combined functions. This will inevitably increase the number of elements and mounting holes and cause structure redundancy. In control principle, the reciprocating spool main stage of multi-way valve is similar to reversing valve of industrial hydraulic valve, which can control direction and flow by controlling and changing flow area and characteristic of four throttle ports through the changes of axial relative place between cylinder spool convex shoulders and throttle ports. The reciprocating movement of spool main stage can be manual control, hydraulic control, pneumatic control, electronic control, electro-hydraulic control, electro-hydraulic proportional control and so on. The principle is a linkage control solution, which makes two controlled chambers of actuator with double loaded cavities rigid synchronous. Therefore, the single controllability of throttle ports is not good enough and cannot satisfy more and more diversified control requirements of throttle ports, especially different configurations of cylinder structure parameters (rod diameter area, differential ratio and so on) for different loaded requirements. This inevitably causes very complicated configurations not only before factory, but also in field. This will make optimization more complicated and difficult.
FIG. 1 is a structure diagram of a commercially available typical multi-way valve product. In FIG. 1, the structure consists of the cylinder spool 1-1-2 with multiple convex shoulders and kinds of circumferential throttle ports and complicated valve body 1-1-1 with multiple undercutting grooves and inner channels and four channels of main ports. There are multiple auxiliary control valves and corresponding mounting holes using screw cartridge valves in valve body, such as the relieve valve 1-1-5 with second-supply-oil function, the pressure compensation valve 1-1-3 with load sensing, the embedded check valve 1-1-4 and corresponding mounting holes. End plates 1-1-6 on both sides of spool 1-1-2 can import oil from outside pilot control system and install mechanism 1-1-7, which can restrict and adjust axial position of spool. This kind of traditional structural products is still at main stream and dominant position currently.
But in recent years, the requirements for hydraulic technology in mobile mechanisms are increasing with each passing day, the requirements for the traditional structure and the way of control are stricter, especially the requirements for spool main stage and valve body are more complicated, which make the complicated machining, structural compliance, single controllability and sensitive factor more prominent. Moreover, the current mobile machinery electro-hydraulic transmission chain faces extraordinary pressure of improving energy efficiency and reducing carbon emissions, which mean higher efficiency of mobile hydraulic transmission and control, more stricter emission standards of host machine, further improving intelligent control and overall coordinated engine energy efficiency. This kind of structure and control of the traditional multi-way valve in FIG. 1 cannot meet the requirements of application and currently faces new challenges and innovations.
Based on the new technical environment and background, the present invention proposes a new technical solution, in FIG. 2-1. The technical solution has carried on product reorganizations and structural innovations substantially for traditional multi-way valve in FIG. 1 from the main structure of valve, circuit control and so on. The innovative modular combined high-voltage electro-hydraulic multi-way valve and system with the function of self-supply-oil pilot control using compact two-way cartridge valves, not only can satisfy the basic control functions of traditional electro-hydraulic valve system and be two connection ways including sandwich and monoblock, but also can satisfy the requirements of higher efficiency, energy saving, lower emission through more kinds and more reasonable modular combined configurable solutions. And the requirements of geometric structure based on seat valve main stage, tolerance matching and precision grade of dimension, the heat treatments of materials and processing inspective technology, and the finish machining of special throttle ports are much less strict than the traditional structure. Especially, it has better “single controllability” for the control. From the above, it overall improves the space of “manufacturability”, “assemblability”, “maintainability”. Therefore, it has avoided structural defect of difficult to manufacture because of complicated structure and incompliant structure and is good for the changing of manufacturing mode from the traditional way to the mass customized way. It will significantly and positively influence the development of mobile hydraulic control valve and combinations.